body {
    font-family: 'Arial', sans-serif;
    background-color: #f4f4f4;
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.container {
    background-color: #fff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    width: 300px; /* 设置容器宽度，根据需要调整 */
}

h2 {
    text-align: center;
    color: #333;
}

.form-group {
    margin-bottom: 16px;
}

label {
    display: block;
    margin-bottom: 8px;
    color: #555;
}

input {
    width: 100%;
    padding: 8px;
    box-sizing: border-box;
    border: 1px solid #ccc;
    border-radius: 4px;
}

input[type="submit"] {
    background-color: #4caf50;
    color: #fff;
    cursor: pointer;
}